1. Field of the Invention
This invention relates to heavy duty mining apparatus. In particular, it pertains to an improved cutting head for a continuous surface miner.
2. Background Art
Heavy duty continuous surface mining machines provide an efficient means for mining mineral deposits located close to the surface of the earth. Such machines usually take the form of tracked vehicles which are self propelled in a path of travel parallel to the surface of the mineral deposits to be mined. The mining machines include elongated, rotatable, heavy duty cutting heads that are oriented generally perpendicular to the path of travel of the mining vehicle and which include cutting teeth for loosening the mineral deposit into a disturbed composite. The cutting head alone of a continuous surface mining machine may weigh as much as thirty thousand pounds and be as much as seven feet in diameter and thirteen feet in width. The cutting heads may be rotated as fast as 60 revolutions per minute to produce over twenty-five hundred tons of disturbed mineral composite per hour.
Although continuous surface mining machines have proven to be the most cost effective way to mine mineral deposits located close to the surface of the earth, it will be appreciated that the rotation of a massive cutting head in contact with a contiguous mineral deposit places excessive strains on the mining apparatus. In particular, the cutting teeth of the head can experience rapid deterioration, and the bearings that rotatably mount the cutter head to the chassis of a mining machine may be subjected to uneven wear. It will also be appreciated that mineral deposits loosened by the cutting head must be collected in some manner for subsequent transfer of the composite from the mine.
Cutting heads for continuous surface mining machines in the past have been provided with detachable teeth so that worn cutting teeth may be replaced by new teeth. Notwithstanding the detachable nature of conventional cutting head teeth, replacement of such conventional teeth has proven to be an awkward and time-consuming procedure. Moreover, previous continuous surface mining machines have relied solely on the passage of the cutting arms and teeth through the disturbed loosened mineral deposits to throw the loosened composite rearwardly and upwardly to a conveyer belt within the mining machine for collection of the composite. Since the cutting arms and individual cutting teeth supported by the cutting arms are advantageously longitudinally and radially spaced apart from each other, a significant portion of the loosened composite is not contacted by the cutting teeth or arms, and is therefore not collected by the mining machine's conveyer.